Do not worry, now if you have it, you can use another phone to send a special SMS to manage and disable silent mode to normal mode or ringing. Where's my droid can also set a maximum volume level so that it is easier to find.
With applications where's my droid, you can also find the location of your phone's GPS coordinates in latitude and longitude and a link to Google Maps so you can find your cell phone's location.
Download Android App Where's My Droid.
https://play.google.com/store/apps/details?id=com.alienmanfc6.wheresmyandroid